sqsh(1) User Contributed Perl Documentation sqsh(1)NAMEsqsh - Interactive database shell (version 2.1.7)
SYNOPSISsqsh [[options]] [[args......]]
[ -a count ]
[ -A packet_size ]
[ -b ]
[ -B ]
[ -c [cmdend] ]
[ -C sql ]
[ -d severity ]
[ -D database ]
[ -e ]
[ -E editor ]
[ -f severity ]
[ -G tds_version ]
[ -h ]
[ -H hostname ]
[ -i filename ]
[ -I interfaces ]
[ -J charset ]
[ -k keywords ]
[ -K keytab]
[ -l debug_flags ]
[ -L var=value ]
[ -m style ]
[ -n on|off ]
[ -N appname ]
[ -o filename ]
[ -p ]
[ -P [password] ]
[ -Q query_timeout ]
[ -r [sqshrc] ]
[ -R server principal ]
[ -s colsep ]
[ -S server ]
[ -t [filter] ]
[ -T login_timeout ]
[ -U username ]
[ -v ]
[ -V [bcdimoqru]]
[ -w width ]
[ -X ]
[ -y directory ]
[ -z language ]
[ -Z [secmech|default|none] ]
DESCRIPTION
Sqsh (pronounced skwish) is short for SQshelL (pronounced s-q-shell),
and is intended as a replacement for the venerable 'isql' program
supplied by Sybase. It came about due to years of frustration of trying
to do real work with a program that was never meant to perform real
work.
Sqsh is much more than a nice prompt, it is intended to provide much of
the functionality provided by a good shell, such as variables,
aliasing, redirection, pipes, back-grounding, job control, history,
command substitution, and dynamic configuration. Also, as a by-product
of the design, it is remarkably easy to extend and add functionality.
OPTIONS
The following options may be used to adjust some of the behavior of
sqsh, however a large portion of the configuration options are
available only through environment variables which may be set at
runtime or via a .sqshrc file.
Options may also be supplied in the SQSH environment variable. This
variable is parsed prior to parsing the command line, so in most cases
the command line will override the contents of the variable. Be aware
that for options which are allowed to be supplied multiple times, such
as -c, supplying them both in a variable and on the command line will
be the same as supplying them multiple times on the command line.
-a count
Sets the maximum count of failures (as determined by the
$thresh_fail variable) that may occur before sqsh will abort.
Setting this to 0 indicates that sqsh should not exit on errors.
This value defaults to 0 and may also be set using the $thresh_exit
variable. See section EXIT STATUS for details.
-A packetsize
Specifies the size of the network TDS packets used to communicate
with the SQL server. This value must be between 512 and 8192, and
be a multiple of 512. Check your SQL Server configuration to
determine supported packet sizes. This value may also be specified
at run-time using the $packet_size variable.
-b Suppress the banner message upon startup. This is unnecessary in
cases where stdout has been redirected to a file. This option may
also be set via the $banner variable.
-B Turns off all buffering of stdin, stdout, and stderr. This feature
allows sqsh to be run from an interactive control script such as
chat and expect.
-c [cmdend]
Internally sqsh provides the command \go to send a batch of SQL to
the database and provides a single alias, go for this command. Each
time cmdend is supplied a new alias for \go is established.
-C sql
Causes the sql command to be executed by sqsh, similar to the same
behavior exhibited by the -i flag. This sql statement may not
contain double quotes (this limitation may be lifted in a future
release of sqsh).
-d severity
Sets the minimum SQL Server error severity that will be displayed
to the user. The default is 0, and valid ranges are from 0 to 22.
This may also be set using the $thresh_display variable. See
section EXIT STATUS.
-D database
Causes sqsh to attempt to start with your database context set to
database rather than your default database (usually master). This
may also be set using the $database variable.
-e Includes each command issued to sqsh to be included in the output.
This option may also be set via the $echo variable (which is
unrelated to the \echo command).
-E editor
Set the default editor to editor. This may also be set using the
UNIX environment variable $EDITOR to the name of the editor
desired.
-f severity
Sets the minimum severity level considered a failure by sqsh. This
is the same as setting the $thresh_fail variable. See section EXIT
STATUS for details.
-G tds_version
Set the TDS version to use. Valid versions are 4.0, 4.2, 4.6,
4.9.5, 5.0 and freetds additionally supports versions 7.0 and 8.0.
The specified value is assigned to the variable $tds_version. Input
validation is not performed by sqsh. However, when an invalid TDS
version is specified, the default version of 5.0 will be used.
After a session is setup, the variable $tds_version will be set to
the TDS version in effect. The variable will not be available if
option -G is not used. Meant for test and debugging purposes only.
TDS stands for Tabular Data Stream and is the communication
protocol Sybase and Microsoft uses for Client-Server communication.
-h Turns off column headers and trailing "(# rows affected)" from
batch output.
-H hostname
Sets the client hostname as reported in sysprocesses. This may also
be set via the $hostname variable.
-i filename
Read all input from filename rather than from stdin.
-I interfaces
When a connection is established to the database, the interfaces
file is used to turn the value of $DSQUERY into the hostname and
port to which the connection will be made, by default this is
located in $SYBASE/interfaces. This flag allows this default to be
overridden.
-J charset
Specifies the character set to be used on the client side to
communicate with SQL Server. This may also be set using the
$charset environment variable.
-k keywords
Specifies a file containing a list of keywords to be used for
keyword tab completion, if readline support has been compiled into
sqsh. This file may also be set via the $keyword_file variable,
which defaults to $HOME/.sqsh_words.
-K keytab
Kerberos support. Specify the keytab file name for DCE.
See the Kerberos Support section below for details.
-l debug_flags
If sqsh has been compiled with -DDEBUG, this option may be used to
turn on and off debugging options. See the $debug variable, below.
-L var=value
Sets the value of $var to value. This may be used to set the value
of any sqsh variable even if an explicit command line variable is
supplied for setting the variable. The -L flag may be used to set
the value of non-configuration variables as well.
-m style
Changes the current display style to style. Currently supported
styles are horiz, vert, bcp, csv, html, meta, pretty and none. The
current display style may also be set using the $style variable or
via the -m flag to the \go command.
-n on|off
Enables chained transaction mode on connect (if set to on). Chained
transaction mode is also known as "AutoCommit off" mode.
-N appname
Set the application name sqsh uses to identify itself to the SQL
server. The application name can be retrieved from the server using
the column program_name of the master.dbo.sysprocesses table.
Defaults to sqsh-2.1.7.
-o filename
Redirects all output to filename rather than stdout.
-p Display performance statistics upon completion of every SQL batch.
This option may also be turned on via the $statistics variable, or
by supplying the -p flag to the \go command.
-P [password]
The Sybase password for username required to connect to server
(default, NULL). The password may also be set via $password.
Supplying a password of '-' causes the password to be read from the
first line of stdin.
sqsh takes pains to hide the password from any user trying to view
the command line used to launch sqsh, so using -P should not
constitute a security hole. Alternatively, you can store your
default password in .sqshrc file which is not readable by anyone
other than yourself. (chmod 600 .sqshrc)
-Q value
Query timeout value (equivalent to isql's -t option). If set, will
timeout a long running query. Maps to the $query_timeout variable.
For example:
sqsh-SASE1502 -Usa -P -Q30
ASE1502.sa.master.1> cd tix
ASE1502.sa.tix.1> select count(*) from E_TIX;
Open Client Message
Layer 1, Origin 2, Severity 2, Number 63
ct_results(): user api layer: internal Client Library error:
Read from the server has timed out.
ASE1502: Query or command timeout detected, command/batch cancelled
ASE1502: The client connection has detected this 1 time(s).
See also the $max_timeout variable, which controls the number of
times a timeout may occur on the current connection before the
session is aborted.
-r [sqshrc]
Specifies an alternate .sqshrc file to be processed, rather than
the default. If no sqshrc is supplied following -r, then no
initialization files are processed. This flag must be the first
argument supplied on the command line, all other instances will be
ignored.
-R server_principal
Kerberos support: Specifies a server principal to use for network
(Kerberos) authentication, if the server name in the interfaces
file differs from the real server name.
See the Kerberos Support section below for details.
-s colsep
Causes the string colsep to be used to delimit SQL column output
columns, this defaults to " ".
-S server
The name of the Sybase server to connect, the default of this is
the external environment variable $DSQUERY. If neither -S nor
$DSQUERY is set then defaults to "SYBASE". This value may also be
set via the internal variable $DSQUERY.
-t [filter]
Enables filtering of command batches through an external program,
filter, and prior to being sent to the SQL Server. If filter is not
supplied, then $filter_prog is used (default is 'm4 -'). This value
may also be set via the $filter and $filter_prog variables.
-T value
Specifies the login timeout (similar to isql's -l flag). If set
specifies the number of seconds sqsh will wait before timing out a
login request. Maps to the $login_timeout variable.
-U username
The Sybase username to connect to the database as, this defaults to
the username of the user running sqsh. The username may also be set
via the $username variable.
-v Displays the version number, $version, and exits.
-V [bcdimoqru]
Kerberos support: Specify the security options to use.
See the Kerberos Support section below for details.
-w width
The maximum output width of a displayed result set, this defaults
to your screen width in interactive mode.
-X Initiates the login connection to the server with client-side
password encryption (if supported). If either SQL Server does not
recognize this option, or if the version of CT-Lib used to compile
sqsh does not support this option, then it will be ignored. This
option may also be set using the $encryption environment variable.
-y directory
Specifies a SYBASE directory to use other than the value of $SYBASE
in order to find the interfaces file.
-z language
Specifies an alternate language to display sqsh prompts and
messages. Without the -z flag, the server's default language will
be used. This may also be set using the $language variable.
-Z [secmech|default|none]
Kerberos support: Specify the security mechanism to use.
See the Kerberos Support section below for details.
args...
If sqsh is run with the -i flag specifying an input file to be
processed (rather than initiating an interactive session),
arguments may be supplied on the command line to be passed to the
input file. These arguments may be accessed using the variables
${0}, ${1}, ... (see the Variables section, below, for more
information).
Initialization
Upon startup, sqsh initializes all internal environment variables,
commands, and aliases to their default values, it then looks in the
system-wide configuration file, /etc/sqshrc, followed by a local
configuration file $HOME/.sqshrc (this may be overridden via the SQSHRC
external environment variable). If this file is found it is executed
just like a script would be using the -i flag.
The .sqshrc file may contain anything that could normally be typed at
the prompt, however it should be noted that at the time this file is
read sqsh has yet to establish a connection to the database, however
most commands that perform database activity, such as \go will attempt
to establish a database connection when executed (it may also prompt
you for a password if necessary). Also, if database activity is
required within this startup file, the \connect command (see COMMANDS,
below) may be executed.
After the .sqshrc file has been executed, sqsh then parses any command
line options (thus any variables set in your .sqshrc file may be
overridden by command line options). Following that, if sqsh is run in
interactive mode (i.e. without -i and if stdin is attached to a tty),
it then looks for .sqsh_history and loads the contents of that file
into this history buffer (see BUFFERS, below).
Immediately prior to establishing a connection to the database (either
during startup, or by an explicit \connect or \reconnect command), the
file $HOME/.sqsh_session is executed. The name of this file may be
overridden using the $session variable.
Command line
When a line is first read by sqsh, the first word is separated from the
line. This word is then expanded of all variables (see Variable
Substitution, below), followed by command expansion (see Command
Substitution, below). The first word of the resulting string is then
analyzed to see if it is either a valid sqsh command or alias.
The sqsh command line follows many of the same rules as Bourne shell,
allowing file redirection, pipelining, command substitution, and back-
grounding via the same syntax.
Comments
Any line beginning with a # followed by a non-alphanumeric character
(any character other than 0-9, a-z, A-Z, and _) causes the entire line
to be ignored. Because of the possible collision with T-SQL session
specific temp-table names, the line will not be ignored if the first
character following the #, is alphanumeric.
Quoting
Quoting is used to prevent the interpretation of special keywords or
characters to sqsh, such as white-space, variable expansion, or command
substitution. There are three types of quoting, escape, single-quotes,
and double-quotes.
Enclosing characters in single quotes preserves the literal
interpretation of each character contained within the quotes. A single
quote may not appear within single quotes, even when preceded by an
escape. For example:
1> \echo I can not expand '$username'
outputs
I can not expand $username
The characters \\ are used to escape the meaning (and thus prevent the
interpretation) of the character immediately following them. The \
character itself may be escaped. For example:
1> \echo I can\\'t expand '$username'
outputs
I can't expand $username
The escape character may also be used to escape a new-line in order to
perform a line continuation, in this case the new-line is discarded and
the continued line is automatically appended to the previous line, for
example:
1> \echo Hello \\
--> World!
Hello World!
Enclosing characters in double quotes preserves the literal meaning of
all characters within them with the exception of $, ', and \\. A double
quote may be contained within double quotes by escaping it.
1> \echo "\\"I can't deny it, I like $username\\", she said"
prints out
"I can't deny it, I like gray", she said
Expansion
After a line of input has been read, sqsh attempts to expand the line
of any aliases (see Aliasing, below), following that it attempts to
determine if the line begins with a command keyword. Once a line has
been determined to contain a command name it has two types of expansion
performed up it: variable substitution, followed by command
substitution respectively. Following this expansion the command line is
separated into words and the command is executed.
Variable Substitution
The character $ is used to indicate variable substitution or expansion
within a word. These variables may be assigned values by the \set
command like so:
1> \set name=value
name may be a character or underscore followed by any combination of
characters, digits, or underscore, and may not contain any special
characters, such as (') and ("). The restriction on the first character
being a digit is introduced because SQL allows the representation of
money data types as $nn.nn where n is a digit.
value may contain anything, however if it is to include white-space,
then it must be quoted (see Words & Quoting, above). Note that in order
to prevent the expansion of a variable use either single quotes, or two
\'s, like thus:
1> \echo \\$name
$name
Variables may be referenced in one of two ways:
$variable In this manner all characters, digits, and underscores are
treated as the name of the variable until another type of character is
reached (either a special character, or a white-space). ${variable} The
braces are required only when variable is followed by a letter, digit,
or underscore that is not to be interpreted as part of its name. Note
that the same effect may be achieved using double quotes.
It should be noted that because the variables are expanded prior to
breaking the command line into words, if the contents of the variable
contain white spaces, they are treated as significant by the parser. In
the following example:
1> \set x="1 2 3"
1> \echo $x
the \echo command receives three arguments, "1", "2", and "3", although
it looks as if only one argument was passed to it. This behavior is
consistent with most shells (such as csh, bourne shell, etc.).
Command Substitution
Sqsh supports a second form of expansion called command substitution.
This form of expansion substitutes a command on the command line with
the output of the external UNIX command. This expansion may be achieved
by placing the command line to be executed in back-quotes (`). For
example:
1> \set password=`/sybase/bin/getpwd $DSQUERY`
1> \echo $password
ilikepickles
This example, the external program /sybase/bin/getpwd is executed with
the current contents of the $DSQUERY environment variable, the entire
expression is then replaced with the output of getpwd (ilikepickles)
prior to executing the \set command. By default, the output of the
substituted command is first broken into words according to the
contents of the $ifs variable prior to assembling together back into
the command line. So, by overriding the contents of $ifs you may affect
the behavior of the substitution process.
For example:
1> \set ifs=":"
1> \echo `echo hello:how:are:you`
hello how are you
This mechanism is frequently useful for parsing input files, such as
/etc/passwd into fields.
Input/Output Redirection
As with standard Bourne shell (and most other shells, for that matter),
a command's input and output may be redirected using a special notation
interpreted by the shell. The following may appear anywhere on the
command line, but only redirection that is specified prior to a pipe
(|) actually has any effect on the behavior of internal sqsh commands
(refer to Pipes, below).
<word
Use the file word as the standard input for the command. Typically
very few sqsh commands actually read anything from stdin, so this
will usually have no effect (see the \loop command).
[n]>word
Associate the output of file descriptor n (stdout, by default) with
file word. If this file does not exist it is created; otherwise it
is truncated to zero length.
[n]>>word
Append the output of file descriptor n (stdout, by default) to file
word, creating it if it does not exist.
[m]>&n
Redirect the output of file descriptor m (stdout by default), to
same output as file descriptor n. The order in which redirections
are specified on the command line is significant, as the
redirections are evaluated left-to-right. For example:
1> select * from select /* syntax error */
2> \go >/tmp/output 2>&1
This statement first redirects the standard output of the \go
command to the file /tmp/output, then redirects the stderr to the
same file. So, when the commands fails, the error output will be
found in the file /tmp/output.
However, by changing the order of redirection, you can completely
change the meaning:
1> select * from select
2> \go 2>&1 >/tmp/output
Msg 156, Level 15, State 1
Server 'SQSH_TEST', Line 1
Incorrect syntax near the keyword 'select'.
In this case, error output will be sent to stdout, while what would
have gone to stdout is redirected to /tmp/output (in this case
/tmp/output will be empty).
Please read the section on Background Jobs, below, for detailed info on
the interaction between file redirection and background jobs.
Pipes
A pipeline is a sequence of one or more commands separated by a '|',
each command using the stdout of the preceding program for its own
stdin. However the first command in the pipeline must be a sqsh
command, and all other commands must be external (or UNIX) programs.
Any sqsh command may be run through a pipeline, although for many of
them (such as the \set command) it doesn't really make any sense to do
this. The following is an example of a pipeline:
1> select * from syslogins
2> \go | more
This command causes the result set generated by the \go command to be
sent to the more(1) program, which then sends it to your screen,
pausing at each screen full of data (this is the primary reason that I
wrote sqsh).
There are several peculiarities in the way in which sqsh deals with
pipelines as opposed to the way in which standard Bourne shell treats
them.
Everything following the first occurrence of a pipe (|) character is
broken into white-space delimited words, including such special shell
commands as '2>&1' and other occurrences of pipes. If there are any
variables contained in these words they are expanded following the same
quoting rules as described in Words & Quoting, above, with the one
exception that all quotes are left in place. These words are then
reassembled into a single string and shipped off to /bin/sh for
processing.
In short, sqsh makes no attempt to interpret what follows the first
pipe, instead it is shipped off to a "real" shell to do the work. The
rationale behind this is that I was lazy and didn't feel like writing
all of the same bizarre variable handling, &&'ing, ||'ing, grouping,
and variable expansion rules that Bourne shell supports, and instead I
let Bourne do the dirty work.
The advantage of this method is that you can do some very complex stuff
after the pipeline, such as:
1> select * from syscolumns
2> \go | (cd /tmp; compress -c > sysolumns.Z)
Not that I can think of any real reason to do this...but you can if you
want to.
Background Jobs
Backgrounding provides a mechanism whereby you may run any sqsh command
as a background process and continue working while it runs. Sqsh offers
two types of backgrounding:
Deferred
In this mode sqsh redirects all output of the background job to a
temporary file (located in the directory $tmp_dir) while the job is
running, so that the output is not intermixed with what you are
currently working on. When the job completes you are notified of
the process completion and the output may be viewed using the \show
command.
Non-Deferred
This corresponds to the common idea of a background process under
UNIX. In this mode the output of the job is not implicitly
redirected for you, and thus may become intermingled with what you
are currently working. The mode selection you choose is selectable
via the $defer_bg variable (which defaults to '1', or 'On').
Typically the only reason to not use deferred mode is to prevent
large result sets from filling up your file system.
To specify that a job be run in the background, simply append a & to
the end of the command line, as:
1> sp_long_arduous_proc 1, 30
2> \go &
Job #1 running [xxxx]
1>
When sqsh encounters the & on the end of the command line it spawns a
child process (with a Unix process id of xxxx) then the child process
calls the \go. \go command then establishes a new connection to the
database (using the current values of the $DSQUERY, $username,
$password variables) and executes the shown query. While the job is
executing the commands \jobs \wait and \kill may be used to monitor or
alter a currently running job (see section COMMANDS, below). When any
job completes sqsh will display a notification, such as:
1> select count(*) from <return>
Job #1 complete (output pending)
2>
When a job completes, if it had no output, it is immediately considered
terminated and will not show up in the current list of running jobs.
However if the complete job has pending output, it will continue to be
displayed as a running job (with the \jobs command) until a \show is
used to display the output of the job.
There is a known bug with job backgrounding when used in conjunction
with pipes, please refer to the BUGS section at the end of the manual.
Buffers
In normal isql only two buffers are maintained; the buffer into which
you are currently typing, and a buffer that contains the last batch
executed (this is kept around for when you run 'vi', or 'edit').
Sqsh maintains several distinct sets of buffers:
Work Buffer: This buffer corresponds directly to the isql work buffer.
It is the buffer into which you enter the current batch prior to
sending it to the database.
History Buffer: This is actually a chain of 0 or more buffers
(configurable by the $histsize variable) of the last $histsize batches
that have been run. This buffer is only maintained when sqsh is run in
interactive mode; that is, batches executed using the -i flag, or
executed via redirection from the UNIX prompt will not be maintained in
history (after all, they are already in a file somewhere).
If the variable $histsave is True (see section SPECIAL VARIABLES), and
sqsh is in interactive mode, then the current history buffer is written
to $HOME/.sqsh_history when you exit. This file is then read back into
sqsh the next time it is started in interactive mode.
Named Buffers: At any time during a session the Work Buffer, or any of
the History Buffers may be copied into a named buffer using the
\buf-copy command (see section COMMANDS, below). These buffers are lost
when you exit (however you may use the \buf-save command to save named
buffers to a file).
Buffer Short-Hand
Many commands allow all of these buffers to be referenced in a short-
hand fashion, very similar to the way that csh(1) references its
commands history. Any of these shorthands may be used for any buffer
parameter described in the COMMANDS section:
!. The current work buffer.
!! The last command executed (note, this is not available in non-
interactive mode as it does not maintain a history).
!+ The next available history entry. This is a write-only buffer, so
typically only applies to such commands as \buf-copy.
!n Refers to history #n. Each time an entry is written to history it
is assigned an increasing number from the last entry, with this
short-hand you may reference any given history.
!buf_name
Just for consistency this is supplied as a reference to named
buffer buf_name, however buf_name without the leading '!' is also
considered correct.
buf_name
Refers to the named buffer buf_name.
Variables
Variables may also be contained within work buffers. Under these
circumstances the variables remain unexpanded until the buffer is sent
to the database (via the \go command), during which time they are
expanded and replaced within the buffer. This behavior may be altered
via the $expand variable. (see Special Variables, below).
The following is an example of using variables within a buffer:
1> \set table_name=syscolumns
1> select count(*) from $table_name
2> \go
This is the equivalent of performing the query:
1> select count(*) from syscolumns
2> \go
directly. Typically this feature is useful for reusing large complex
where clauses, or long column names.
Quoting rules apply the same in SQL buffers as they do in command
lines. That is, any variables contained within double quotes (") are
expanded and variables contained within single quotes (') are left
untouched. Thus:
1> select "$username", '$username'
2> \go
yields the results
---- ---------
gray $username
Command Substitution
As with the command line, the output of UNIX commands may also be
substituted within a SQL buffer upon execution (once again, only if the
$expand variable is set to 1, or true). In this circumstance the
command contained within back quotes (`) is replaced with its output
prior to forwarding the buffer to SQL server. For example:
1> select count(*) from `echo syscolumns`
2> \go
Causes the strings 'echo syscolumns' to be replaced by the word
syscolumns prior to executing the command. It should be noted that the
contents of the substituted command are only executed at the time of
the \go command, not when the line of SQL is input.
Flow-of-Control
New with version 2.0 of sqsh, is the ability to perform basic flow-of-
control and functions using the \if, \while, \do, and \func commands.
Blocks & SQL Buffers
All sqsh flow-of-control commands are block-based. That is, if the test
expression of the command is met, then a block of sqsh-script will be
executed. For example, the definition of the \if command is:
\if expression
block
\fi
This block may be any number of lines of sqsh commands, SQL, or flow-
of-control statements to be executed if the expression evaluates to a
success condition (0).
Each block has its own SQL buffer for the duration that the block is
executed. That is, the following statements:
1> /*
2> ** IMPROPER USAGE OF IF BLOCK
3> */
4> select count(*) from
5> \if [ $x -gt 10 ]
6> sysobjects
7> \else
8> sysindexes
9> \fi
5> go
will yield:
Msg 102, Level 15, State 1
Server 'bps_pro', Line 1
Incorrect syntax near 'from'
because the string 'sysobjects' or 'sysindexes' were inserted into
their own SQL buffers. These buffers are discarded as soon as the end
of the block was reached, and since a \go command was not contained
within the block, no additional errors were generated.
Thus, the correct way to write the above expression would be:
1> /*
2> ** PROPER USAGE OF IF BLOCK
3> */
4> \if [ $x -gt 10 ]
5> select count(*) from sysobjects
6> go
7> \else
8> select count(*) from sysindexes
9> go
10> \fi
or, even:
1> /*
2> ** PROPER USAGE OF IF BLOCK
3> */
4> \if [ $x -gt 10 ]
5> \set table_name=sysobjects
6> \else
7> \set table_name=sysindexes
8> \fi
4> select * from $table_name
5> go
Also, note that the line number displayed in the sqsh prompt resets to
the current position in the outer SQL buffer after reaching the \fi
terminator.
Expressions
All flow-of-control statements in sqsh take an expression to determine
which block of code to execute. Just like UNIX's Bourne Shell, this
expression is simply an operating system program that is executed by
sqsh. If the command returns a success status (calls exit(0)), then it
is considered successful.
For example, with following statement:
\while test $x -lt 10
block
\done
will execute the contents of block while the current value of $x is
less than 10. Note that 'test' is a standard UNIX program to perform
basic string or numeric comparisons (among other things). Also, unlike
many shells, sqsh has no built-in version of 'test'.
Sqsh does, however, support the standard short form of 'test':
\while [ $x -lt 10 ]
block
\done
With this expression the open brace ('[') is replaced by the sqsh
parser with 'test', and the close brace (']') is discarded.
Unsupported Expressions
Currently sqsh does not support the standard shell predicate operators
'&&' and '||'. These can be performed like so:
\if sh -c "cmd1 && cmd2"
block
\done
\if statement
The \if command performs conditional execution of a sqsh block based
upon the outcome of a supplied expression:
\if expr1
block1
\elif expr2
block2
\else
block3
\fi
In this example, if expression expr1 evaluates to true, then the block
block1 is evaluated. Otherwise, if the expression expr2 evaluates to
true, then block block2 is evaluated. Finally, if all other tests fail
block3 is evaluated.
Note that, unlike Bourne Shell, every \if command must be accompanies
by a trailing \fi statement. Also the sqsh parser is not terribly
intelligent: The \else and \fi statements must be the only contents on
the line in which they appear, and they may not be aliased to another
name.
\while statement
The \while command executes a block of sqsh code for the while a
supplied expression remains true.
\while expr
block
\done
In this example, while the expression expr evaluates to true, then the
block block is evaluated.
The \break statement may be used to break out of the inner-most \while
or \for loop (more on \for below).
\for statement
The \for command executes a block of sqsh code for each word supplied:
\for var in word ...
block
\done
For each word supplied, the value of the variable $var is set to the
word and the block of code is executed. Execution ends when there are
no more words in the list.
As with \while the \break statement may be used to break out of the
inner-most execution loop.
\do command
The \do command is kind of a cross between a statement and a command.
It is a form of \go (see below for details on the \go command) in which
a block of sqsh code may be executed for each row of data returned from
the query. When the block is executed, special sqsh variables #[0-9]+
(a hash followed by a number) may be used to reference the values in
the returned query. For example the following command:
select id, name from master..sysdatabases
\do
\echo "Checkpointing database #2, dbid #1"
use #2
go
checkpoint
go
\done
would cause a CHECKPOINT command to be issued in each database on the
server.
Command line options
The \do command establishes a new connection to be used by the block of
code when executed. By default, this connection is established to the
current server (the current setting of $DSQUERY), using the current
username ($username) and the current password ($password). This
behavior may, however, be overridden using command line options:
-D database
Establishes the connection to the database as the supplied
database.
-U username
Establishes the connection to the server as the supplied username.
-P password
Establishes the connection to the server using the supplied
password (which is hopefully a valid password for the supplied
username).
-S server
Establishes the connection to the supplied server.
-n Do not create a connection for use by the \do loop. This flag is
mutually exclusive with the above flags. With this flag enabled,
attempts to perform database commands within the block will
generate a flurry of CT-Library errors.
Column variables
As mentioned above, the values of the columns in the current result set
may be determined using the special #[0-9]+ variables. Thus, the
variable #1 would contain the value of column number one of the current
result set, and #122 could contain the value of the 122'nd column
(column numbers begin at 1).
In the case of nested \do loops, values in previous nesting levels may
be referred to by simply appending an addition '#' for each previous
nesting level, like so:
select id, name from sysobjects
\do
select name, indid from sysindexes where id = #1
\do
\echo "Table ##2 (objid ##1) has index #1"
\done
\done
obviously, this isn't the way you would do this query in real life, but
you get the idea.
When expanding columns with NULL values, the column variable will
expand to an empty string (''). Also, references to non-existent
columns, such as #0, will result in an empty string ('').
As with regular sqsh variables (those referenced with a '$'), column
variables will not be expanded when contained within single quotes.
Aborting
If the \break or \return commands are issued during the processing of a
\do loop, the current query will be canceled, the connection used by
the loop will be closed (unless the -n flag was supplied) and the \do
loop will abort.
\func command
The \func command is used to define a reusable block of sqsh code as a
function. Functions are defined like so:
\func stats
\if [ $# -ne 1 ]
\echo "use: stats [on | off]"
\return 1
\fi
set statistics io ${1}
set statistics time ${1}
go
\done
In this example a new function is established called stats that expects
a single argument, either "on" or "off". Using this argument, stats
will enable or disable time-based and I/O-based statistics.
Once established, the function may be called like so:
\call stats on
Causing all instances of ${1} to be replaced with the first command
line argument to stats.
Command line options
Currently only one command line argument is available to the \func
command.
-x Causes the function to be exported as a sqsh command. That is, the
function may be invoked directly without requiring the \call
command. This behavior is optional because command names can
potentially conflict with T-SQL keywords. When using this flag it
is recommended that you prepend a backslash (\) to your function
name.
Function variables
As shown in the example above, several special variables are available
for use within the body of the function. These are:
$# Expands to the number of arguments supplied to the function or
script when invoked.
$* Expands to the complete list of arguments supplied to the function
or script when invoked.
${0}..${N}
Expands to positional arguments to the function. ${0} is the name
of the function being invoked, ${1} is the first argument, ${2} the
second and so-on, up to argument N. Note that, unlike most shells,
sqsh requires that function arguments be referred to using the
special curly brace syntax (${1}, rather than $1). The reason for
this is that $1 is a valid MONEY value and using the curly braces
gets rid of this ambiguity.
$? After the invocation of a function, this will contain its return
value (see below).
Return value
A value may be returned from a function via the \return command.
Like so:
\return N
Where N is a positive value. This return value is available to the
caller of the function via the $? variable. As convention, a return
value of 0 is used to indicate a success.
If \return is not explicitly called, the default return value is the
current value of the $? variable (which is set to 0 upon entry of the
function). Thus, if any SQL statements are invoked within the
function, the default return value of $? will be the last error code
returned during the processing of the SQL statement.
Kerberos Support
Starting with version 2.1.6, sqsh provides the same command line
options as isql to handle Kerberos network authentication.
In version 2.1.5 experimental Kerberos support was added using the -K
and -R options. -K was merely a switch to set Kerberos on. In sqsh
2.1.6 a more advanced implementation of network authentication is
introduced, although still experimental.
By using the parameters -K, -R, -V, -Z you can make use of your defined
network security settings (libtcl.cfg). The named options are identical
to the ones defined for isql.
-K keytab_file
Keytab_file name for DCE.
-R server_principal
Server principal name when servername specified in interfaces
differs from the real server name.
-V [bcdimoqru]
Specify security options to use with the security mechanism. Each
character stands for a specific security service.
-Z [secmech|default|none]
Request a security mechanism defined for Kerberos, DCE or PAM in
your libtcl.cfg file. Use secmech to specify the name of a SECURITY
entry or default for the first available entry in libtcl.cfg. None
must be specified to disable network authentication or reset
possible existing values in variables $secmech or $secure_options.
For example, connecting to a server using Kerberos (which happens to be
the default, i.e. first entry in libtcl.cfg [SECURITY] tab in this
example):
~> sqsh-SSYB1502 -Uuser1 -RFC6A1502 -Z
\connect: Network authenticated session expires at:
16 Feb 2010 15:28:39 (11764 secs)
SYB1502.user1.master.1> select @@servername,@@authmech,
show_sec_services();
--------------------------- ----------------------------------
FC6A1502 kerberos unifiedlogin delegation mutualauth
integrity confidentiality
detectreplay detectseq
Note that the real name of the server (@@servername) differs from the
server name in the interfaces file, so we have to specify the principal
name through the -R parameter. When you do not specify the -V
parameter together with -Z, all available security options will be
enabled. When -V is specified without any security service options,
only option u for Network Authentication will be implicitly set and the
default security mechanism will be used if -Z is not specified.
[user1@linux-fc6a ~]$ sqsh-SFC6A1502 -Uuser1 -V
Open Client Message
Layer 7, Origin 9, Severity 5, Number 1
ct_connect(): security service layer: internal security control
layer error:
Security service provider internal error -1765328352
occurred.
[user1@linux-fc6a ~]$ kinit
Password for user1@LOCALDOMAIN:
[user1@linux-fc6a ~]$ sqsh-SFC6A1502 -Uuser1 -V
\connect: Network authenticated session expires at:
16 Feb 2010 15:28:39 (10964 secs)
FC6A1502.user1.master.1>
When the connection succeeds, sqsh will store the real name of the
security mechanism in the variable $secmech. For example: "\echo
$secmech" may show csfkrb5. The parameter -V takes a list of characters
from the possible values of bcdimoqru. The option u enables Network
Authentication, is the default and will allways be set when using -V or
-Z, specified or not.
b - chanbinding : Channel binding
c - confidentiality : Data confidentiality service
d - delegation : Allow delegated credentials
i - integrity : Data integrity service
m - mutualauth : Mutual authentication for connection
establishment
o - dataorigin : Data origin stamping service
q - detectseq : Out-of-sequence detection
r - detectreplay : Data replay detection
u - unifiedlogin : Network Authentication
Please check master.dbo.syssecmechs for available services. Non-
existing or not supported services supplied with -V are silently
ignored. If you specify -V and/or -Z, sqsh assumes network
authentication is tried and no password is required.
If you have a network authenticated connection and want to \reconnect
using normal ASE authentication with username and password, you have to
reset the network authentication variables by specifying -Znone
For example:
[user1@linux-fc6a ~]$ sqsh-SFC6A1502 -Uuser1 -V
\connect: Network authenticated session expires at:
16 Feb 2010 15:28:39 (10764 secs)
FC6A1502.user1.master.1> \echo $secmech csfkrb5
FC6A1502.user1.master.1> \reconnect -SASE1502 -Usa -Psybase
Open Client Message
Layer 7, Origin 9, Severity 5, Number 8
ct_connect(): security service layer: internal security control
layer error:
Consistency checks performed on the credential failed
(minor status 0).
FC6A1502.user1.master.1> \reconnect -SASE1502 -Usa -Psybase -Znone
ASE1502.sa.master.1>
The first \reconnect fails because sqsh still wants to try network
authentication. However, no user principal for 'sa' exists and no
ticket is set and thus the connection fails. The second \reconnect
succeeds as the -Znone option reset appropriate variables. If the
Kerberos ticket is renewed with kinit or any other client tool, the
sqsh session must perform a \reconnect to refresh the credentials and
to prevent a premature session abort. With the command \snace you can
request for the session expiration interval. Depending on the security
services that are set, the database connection may be closed without
warning as soon as the ticket expires.
See chapter 16 "External Authentication" from the Sybase System
Administration Guide volume 1 for more information on Kerberos network
authenticationi, e.a.
COMMANDS
Read-Eval-Print
The read-eval-print loop is the heart of the sqsh system and is
responsible for prompting a user for input and determining what should
be done with it. Typically this loop is for internal use only, however
they are open to the user because there are some creative things that
can be done with them.
\loop [-i] [-n] [-e sql] [file]
The \loop command reads input either from a file, a supplied SQL
statement, or from a user (see the options below), determining
whether the current line is a portion of a TSQL statement or a sqsh
command, and performing the appropriate action. When run in an
interactive mode \loop is also responsible for displaying the
current prompt (see $prompt below).
\loop completes when all input has been depleted (end-of-file is
encountered) or when a command, such as \exit requests that \loop
exit.
-i Normally, if file is supplied and does not exist, \loop will
return with an error condition, usually causing sqsh to exit.
By supplying the -i flag, control will be returned to the
calling loop as if end-of-file had been reached (that is, with
no error condition).
-n By default, \loop will automatically attempt to connect to the
database if a connection has not already been established via
the \connect command. The -n flag disables this behavior
allowing \loop to process commands that do not require database
support.
-e sql
Causes \loop to process the contents of sql as if the user had
typed it at the prompt and an implicit call to \go is
automatically appended to the statement. If multiple instances
of -e are supplied, they are all sent as a single batch to the
SQL Server for processing. This option may not be used in
combination with a file name as well.
file
Specifies the name of a file to be used as input rather than
reading input from the user or from the -e flag.
Database Access
Given the size and complexity of sqsh (just look at the length of this
man page), it is amazing how few database manipulation commands that
there actually are. The following are commands that affect or use the
current database connection:
\connect [-c] [-D db] [-S srv] [-U user] [-P pass] [-I ifile] [-K
keytab] [-R server_principal] [-n] [-N appname] [-Q query_timeout] [-T
login_timeout] [-V [bcdimoqru]] [-Z [secmech|default|none]]
This command is used primarily for internal use to establish a
connection to a database. If a connection is already established it
has no effect, however if a connection has not been established and
$password has not been supplied, then the password is requested and
a connection is established. \connect accepts the following
parameters:
-c By default, the \connect command uses the contents of $database
to determine the database context that should be used upon
establishing the connection (this is used by \reconnect to
preserve the current database context upon reconnection). The
-c flag suppresses this behavior and the default database
context of login is used instead.
-D db
Causes \connect to attempt to automatically switch the database
context to db after establishing the connection.
Using this flag is identical to setting the $database variable
prior to establishing the connection.
-S srv
The name of the Sybase server to connect, this defaults to
$DSQUERY if not supplied.
-U user
The Sybase user to connect to the database as, this defaults to
$username variable if not supplied.
-P pass
The password for user required to connect to server. This
defaults to $password if not supplied.
-I ifile
The full path of an alternate Sybase interfaces file to use.
-K keytab_file
Used for DCE user authentication.
-R principal_name
Use for Kerberos user authentication to specify the name of the
server principal when the name differs from the $DSQUERY value.
See also the discussion on Kerberos support.
-n Specifies that the connection must use ANSI compliant chained
mode.
-N appname
Specify the application name the server will use for
program_name in the sysprocesses table.
-Q query_timeout
Set a query timeout period in seconds.
-T login_timeout
Specifies a maximum wait time for session setup.
-V [bcdimoqru]
Security services used for Kerberos support and other security
mechanisms.
-Z [secmech|default|none]
Specifies the security mechanism to use for user
authentication. For example csfkrb5 for Kerberos support.
\reconnect [-c] [-D db] [-S srv] [-U user] [-P pass] [-I ifile] [-K
keytab] [-R server_principal] [-n] [-N appname] [-Q query_timeout] [-T
login_timeout] [-V [bcdimoqru]] [-Z [secmech|default|noe]]
The \reconnect command may be used to force a reconnection to the
database using a new username, server name, or password (if
desired). If this command fails, the current connection remains (if
there is any), however if it succeeds then the current connection
is closed and the new connection becomes the only active one.
All arguments that are accepted by \connect are also accepted by
\reconnect (in fact \reconnect uses \connect to establish the new
connection).
\snace
Will show the session expiration interval for a network
authenticated session, using Kerberos tickets, for example.
\go [options] [xacts]
Sends the contents of the Work Buffer to the database, establishing
a new connection to the database if one does not already exist (by
calling the \connect above). It them displays the results of the
query back to stdout and returns, causing the Work Buffer to be
cleared and moved to the end of the History Buffer.
If the Work Buffer is empty and the $repeat_batch variable is set
to "On", \go will attempt to re-run the last command executed (this
will only work in interactive mode if history support is enabled).
\go accepts the following arguments:
-d display
If X11 support is compiled into sqsh, and X display mode is
being used (see -x, below), then display will be used as the X
display area for the result set. By default the environment
variable $DISPLAY is assumed.
-f Turns off the display of the footer message "(%d rows
affected)". Footer messages may also be turned off via the
$footers variable.
-h Turns off all column headers. These may also be turned off via
the $headers variable.
-m style
Temporarily changes the display style to style for the duration
of the command. Currently supported styles are horiz (or hor or
horizontal), vert (or vertical), bcp, csv, html, meta, pretty
and none. The display style may be permanently set via the
$style variable or the -m command line flag.
-n Turns off variable expansion in the Work Buffer prior to
sending it to the server, this may also be turned off via the
$expand variable.
-p Turns on output of performance statistics when the result set
has been successfully returned from the server. This may also
be turned on via the -p command line argument to sqsh, or the
$statistics variable.
-s sec
If the value of xacts is greater than 1, this causes sqsh to
sleep for sec seconds before executing the next transaction.
Note that the time spent sleeping is excluded from the
statistical information displayed with the -p flag.
-t [filter]
Filters the command batch through an external program, filter,
and prior to being sent to the SQL Server. If filter is not
supplied, then $filter_prog is used (default is 'm4 -'). This
value may also be set via the $filter and $filter_prog
variables.
-w width
Overrides the value of $width for the life of the query (see
$width below).
-x [xgeom]
Turns on the X11 display filter (only if X11 support is
compiled into sqsh), which causes the result set to be sent to
a separate window. If xgeom is supplied, then this value will
be used as $xgeom for the life of the query (see $xgeom below).
-T xwin_title
Specify the title name of the X result window to create. This
will temporarily override the value of $xwin_title. Only useful
to specify -T in conjunction with -x.
xacts
Specifies number of times the contents of the Work Buffer
should be executed. Note that, similar to isql, a result set
will only be displayed during the final execution of the batch.
Also, the contents of the Work Buffer are only expanded once,
prior to the first execution, so the contents of the buffer
will not change between subsequent executions.
\bcp [bcp_options] table
The \bcp commands acts as a sort of enhanced \go command that
redirects the result set(s) of the batch to another server via the
bcp protocol. While it is possible to \bcp the result set back to
the current server (the $DSQUERY variable), this is achieved more
easily via a SELECT INTO.
The nitty-gritty details of \bcp go like this: First the current
SQL batch is expanded (unless the $expand variable is set to 0) and
shipped off to the database for processing. If all goes well, a new
connection is established to the destination database (as specified
via $DSQUERY or the -S flag) to transfer the result set using bcp.
Then, the output of the source database connection is bound to the
new bcp connection and data transfer is performed. \bcp can handle
multiple result sets without any problem (including result sets
returned from stored procedures, etc.) provided that all of the
result sets are valid for the destination table.
The equivalent of a "bcp out" may be performed using the bcp
display style setting and file redirection (see the $style
variable).
-A packet
Specifies the TDS packet size used to communicate with the
destination server. If not supplied this defaults to the value
the $packet_size variable, or (if that is not set), the default
server packet size (usually 512 bytes).
-b batch_size
The number of records transferred in a single transaction
between servers. Note that reaching the end of a result causes
the batch to be transferred, regardless of the value of
batch_size. The default is the entire result set.
-I ifile
The full path of an alternate Sybase interfaces file to use.
-J charset
Specifies the default charset used to communicate with the SQL
Server. This defaults to the current character set (the value
of the $charset variable).
-m maxerr
The maximum number of batches that may fail before \bcp gives
up the ghost (default is 10). Note that this only refers to
failures within a given batch. When performing a bcp of
multiple result sets to a server, if a given result set has,
say, too many columns or bad data types, then the entire bcp
process is aborted regardless of the value of maxerr.
-N Indicates that the value for an identity column in the
destination table is being supplied within the result set.
-P password
The password for user required to connect to server. This
defaults to $password if not supplied.
-S server
The name of the Sybase server to connect, this defaults to
$DSQUERY if not supplied.
-U user
The Sybase user to connect to the database as, this defaults to
$username variable if not supplied.
-X Causes password negotiation with the destination server to be
performed using client-side encryption.
-z language
Specifies the language setting to use.
table
As with regular bcp, table may be either a fully or partially
specified table name in the destination server. Note that since
a new database connection is established during the bcp
processes that the database context of the connection may not
be the same as the current context, so it is usually safest to
fully specify the table name in the form database.owner.table.
\rpc [rpc_opt] rpc_name [[parm_opt] [@var=]value ...]
The \rpc command is used to directly invoke a stored procedure call
in the connected server. This command is particularly useful for
communicating with an Open Server that does not directly support
language calls.
\rpc invokes the remote procedure rpc_name with one or more
parameters that may be named (using @var) or anonymous (by not
supplying a name). Unfortunately, due to the fact that Sybase's
implementation of RPC's, does not directly support most implicit
data type conversions (mainly between VARCHAR (the string you
supply on the command line) and the most other data types (that the
remote procedure is expecting), the syntax for the \rpc command is
somewhat complex. However, in short here is how things work:
As the \rpc command line is being parsed, sqsh attempts to guess
the data type of the parameter value based on the format (for
example if it contains only digits, it is assumed to be an
integer), sqsh then performs an explicit data type conversion prior
to calling the remote procedure call. If sqsh guesses wrong,
several flags are supplied to force it to perform the correct data
type conversion (see parm_opt).
Display Options
The following options may be supplied anywhere on the command line and
are used to affect the manner in which the result set(s) returning from
the remote procedure call are displayed:
-d display
If X support is compiled into sqsh, the value of display is used as
the X windows DISPLAY variable. Note, this is usually supplied with
the -x flag, below.
-f Turns off the display of the footer message "(%d rows affected)".
Footer messages may also be turned off via the $footers variable.
-h Turns off all column headers. These may also be turned off via the
$headers variable.
-m style
Temporarily changes the display style to style for the duration of
the command. Currently supported styles are horiz (or hor or
horizontal), vert (or vertical), bcp, csv, html, meta, pretty and
none. The display style may be permanently set via the $style
variable or the -m command line flag.
-r Request to recompile the procedure prior to execution.
-w width
Temporarily sets the output width to width. The output width may be
permanently set via the $width variable.
-x [xgeom]
Sends output to a separate X window. If xgeom is supplied, then the
X window uses this geometry (see $xgeom for details).
-T xwin_title
Specify the title name of the X result window to create. This will
temporarily override the value of $xwin_title. Only useful to
specify -T in conjunction with -x.
Parameter Options
The following options may be supplied immediately prior to specifying a
parameter value and are used to affect the way in which sqsh interprets
the contents of the value prior to calling the remote procedure.
Although sqsh will allow any combination of these parameters to be
combined, it only really makes sense to combine the -x flag with any
other flag.
-b Indicates that the value that is specified should be converted to
VARBINARY before calling rpc_name. This flag is implicit (i.e. you
need not supply it) if value starts with "0x" and contains only
digits.
-c Indicates that the value that is specified should be converted to
VARCHAR prior to calling rpc_name. This flag is implicit if value
does not match any of the implicit conversions for the other data
types.
-d Indicates that the value that is specified should be converted to
double (float) before calling rpc_name. This flag is implicit if
value is in valid floating point notation (e.g. 0.1, .1, 1.4e10, or
4e10).
-i Indicates that the value that is specified should be converted to
integer (int) before calling rpc_name. This flag is implicit if
value contains only digits (and, optionally, a leading sign).
-y Indicates that the value that is specified should be converted to
money before calling rpc_name. This flag is implicit if value
begins with a "$", and contains only digits and, optionally, a
decimal.
-n Indicates that the value that is specified should be converted to
numeric before calling rpc_name. This flag is never implicit, as
value would always match either int (-i) or float (-d); however,
both of these types will implicitly be converted to a numeric as
necessary by the procedure call.
-u Indicates that value should be ignored and treated as a NULL value,
This flag is implicit if value is "".
Buffers
The following commands may be used to create, destroy, or manipulate
the various buffers described in the BUFFERS section, above.
\clear
The \clear command will discard the current buffer and in
contradiction with the \reset command, will not save the current
buffer to the history. When sqsh is compiled with readline support,
this command will also clear the screen. (as ^l does.) The alias
clear is automatically established upon startup.
\history [-i] [-x count]
Displays the last $histsize batches that have either been sent to
the database via the \go command or cleared from the Work Buffer
via the \reset command. With option -i also display the number of
times the buffer is used and the last time the buffer was used.
This information may be of special interest when using the
$histunique feature. The -x option may specify the number of most
recent history entries to display instead of the total list of
history entries.
\hist-load [filename]
Load a history file and append items to the current history list.
Use $history if no filename is specified as a parameter.
\hist-save [filename]
Will save the current history buffers to the $history file or to
the filename specified as a parameter.
\redraw
Returns a request back to the current read-eval-print loop for it
to redisplay the current Work Buffer. If run from non-interactive
mode, this command has no effect.
\reset
The \reset command corresponds directly to the isql 'reset'
command, returning a request to the read-eval-print loop to clear
the contents of the current Work Buffer and, if you are running in
interactive mode, place a copy of the buffer into the History
Buffer. The alias reset is automatically established upon startup
of sqsh for backward compatibility with isql.
\buf-append dst-buffer [src-buffer]
Appends the contents of src-buffer (defaults to !.) to the contents
of dst-buffer, if it exists. If dst-buffer doesn't exist it is
created.
\buf-copy dst-buffer [src-buffer]
Copies the contents of src-buffer (defaults to !., the Work Buffer,
if not supplied), to dst-buffer. Refer to BUFFERS for information
on buffer naming conventions.
\buf-del [buffer|range]
Remove a history buffer from the history list. You can also specify
a range list consisting of the first and last buffer numbers
separated by a '-'. For example: "\buf-del 1-10" will delete the
first 10 history entries. Another example, "\buf-del 21" will only
delete buffer number 21. Note that the history buffers will be
renumbered consecutively.
\buf-edit [-r read-buf] [-w write-buf]
The \buf-edit command is used to edit the contents of a buffer and
place the changes into another buffer. This command may only be run
while in interactive mode. If read-buf is not supplied then the
buffer to be edited defaults to !., if it is not empty, otherwise
it defaults to !!. If write-buf is not supplied then the edited
buffer is written back to !..
By default, \buf-edit uses the environment variable $EDITOR first,
followed by $VISUAL to determine which editor to use, defaulting to
'vi' if the variable is not set.
It is important to note that as of release 1.2, \buf-edit is no
longer able to use the name of an alias to it as the name of the
editor to launch. This is primarily due to the change in the
behavior of alias (see section Aliasing, below, for details).
The commands edit vi and emacs are automatically established upon
startup of sqsh for backward compatibility with isql.
\buf-get buffer
The \buf-get command is supplied as a shorthand method of running
\buf-copy It is the equivalent of running:
\buf_append !. buffer
\buf-load [-a] filename [dst-buffer]
Copies the contents of filename in dst-buffer (defaults to !.). If
the -a flag is supplied, the contents of filename are appended to
dst-buffer. Note that it is illegal to attempt to write to the
contents of the history buffer.
\buf-save [-a] filename [src-buffer]
Saves the contents of src-buffer (defaults to !.) to filename. If
the -a flag is supplied the contents are appended to filename
rather than overwriting the current contents.
\buf-show [buffer]
Displays the contents of the named buffer. If buffer is not
supplied, then the contents of all named buffers are displayed.
This command is slightly different from the commands above in that
it is only legal to supply a Named Buffer buffer, History Buffers,
and the Work Buffer will have no results.
Variables
The following command(s) are used to manipulate the contents of
internal variables and environment variables.
\set [-x] [name=value ...]
If no arguments are supplied to \set then the current values of all
variables are displayed. Otherwise the variable name is set to
value. Note that some internal variables (see SPECIAL VARIABLES)
may only be set with certain values, so this action may fail,
leaving the previous contents on name intact. The -x flag causes
the variable to be exported to the environment of any programs
launched from sqsh.
Job Control
The following commands are used to view the status of, or manipulate
background jobs that are currently running, these correspond roughly to
the commands supplied by such shells as csh(1).
\jobs [-i]
Displays the status of any currently running jobs, including
whether or not these jobs have pending output, how long they have
been running, and when they were started. The -i option will show
some additional job information. Note that the total run time of
the job is determined from the moment the job is marked complete by
the read-eval-print loop when polled, not when it actually ended
and is flagged as terminated by the signal handler.
\wait [job_id]
Will pause until job designated by job_id completes. If job_id is a
negative number then \wait will pause until any pending jobs
completes. If there are no jobs pending, or job_id does not belong
to a running job, then an error message is displayed. Note that if
multiple jobs are running, and a \wait is issued for one of them,
the other jobs may not automatically get signaled when completed
within the wait period of the specific job. The other jobs may need
to get signaled with a \wait -1 as well to be noticed complete by
sqsh.
\kill job_id
Terminates the job specified by job_id, throwing away any output
that may be deferred for the job. If job_id is not a running job
then an error message is displayed.
\show job_id
Displays the deferred output of completed background job job_id and
removes the job from the list of pending jobs (removing the defer
file in the process). If job_id is still running, or is not a
valid complete job, then an error message is displayed. You may
need to issue a \wait job_id first, to get notified of actual job
completion.
Aliasing
As of release 1.2, sqsh supports full csh-style command aliasing. With
this feature, sqsh checks the first word of each line, prior to any
form of expansion, to see if it matches the name of an existing alias.
If it does, the command is reprocessed with the alias definition
replacing its name. Unlike csh, however, only one form of history
substitution is available within an alias: the '!*' entry, indicating
the current line being expanded. If no history expansion is called for,
the arguments on the command line remain unchanged.
Like csh, aliases are not recursively expanded, so it is perfectly
legal to create an alias that expands to a command by the same name.
The following command is used to create an alias:
\alias [alias_name=alias_body]
If no arguments are supplied to the \alias command, then the list
of aliases currently in effect is displayed. Otherwise, it creates
a new alias with a name of alias_name and a body of alias_body; if
alias_name already exists, the body of the existing alias_name is
replaced with the new definition.
After defining the new alias, whenever sqsh encounters a line
beginning with alias_name, the remainder of the line is replaced
with alias_body before any further processing is performed.
If the string '!*' exists anywhere within alias_body, the arguments
supplied to the alias are inserted at that point, otherwise the
argument are appended to the end of the alias definition. For
example:
1> \alias hi='\echo !* said hello'
1> hi Scott
Scott said hello
where as if the alias does not include the !* keyword, then it
behaves like so:
1> \alias hi='\echo said hello'
1> hi Scott
said hello Scott
It is perfectly legal to include a !* more than once within a given
alias_body. Currently there is no way to escape the string !*, if
you really need this feature send me mail.
\unalias alias_name
Removes alias_name.
Miscellaneous
The left over commands.
\exit [x]
The \exit command requests that current read-eval-print loop cease
processing. When the last loop returns, sqshexit(1)s. You may
specify a exit code as parameter which will be stored in
$exit_value and will be used as return value to the shell upon exit
of sqsh. (0 <= x <= 255).
\abort
Causes all nested read-eval-print loops to abort processing,
causing sqsh to exit with an exit value of 254 (see section EXIT
STATUS).
\read [-a] [-n] [-h] var_name
Reads a line of input from the user, placing the text of the line
in the variable var_name. If the -n is used, then the trailing new-
line is left on the line of text, and if -a is supplied, then the
text of the line is appended to the existing value of var_name. The
-h flag turns off echoing of typed characters back to the user.
\sleep seconds
Causes sqsh too pause for seconds. This is useful within scripts of
batches which need to pause briefly between batches (it was
primarily useful to me for testing background jobs).
\echo [-n] [args ...]
Just like the UNIX echo(1), this prints its arguments to stdout,
followed by a new-line. If the -n flag is supplied, the newline is
omitted.
\warranty
Displays the standard GNU warranty.
\help [command]
Without any arguments \help displays a brief list of all available
commands, otherwise, it provides specific help for command, if
available. When help is requested on a specific command, \help
looks for the file $help_dir/command.hlp and displays it to stdout.
\shell [shell command]
If shell command is not supplied then sqsh executes $SHELL. If the
$SHELL variable has not been set, then, by default, /bin/sh is
executed. Otherwise, if shell command is supplied then it is
executed. The exit status of the command executed is stored in the
special $? read-only environment variable.
\lock
Locks the current session until the correct password is typed. By
default \lock attempts to use the UNIX password (from /etc/passwd)
associated with the user running sqsh, however if the $lock
variable is set then the contents of that is used for validation
instead.
Note, on systems using Shadow Passwords (in which even the
encrypted password is unavailable), \lock will only work using the
$lock variable.
Aliases
The following aliases are established upon startup of sqsh, and are
provided primarily for backward compatibility with isql. These may be
removed at any time using the \unalias command (either at the prompt,
or within your .sqshrc file).
! The ! alias is provided as a csh(1)-like history mechanism, and is
an alias of \buf-append. With release 0.7, this alias is provided
only for backwards compatibility with previous releases of sqsh.
See SPECIAL VARIABLES, $history_shorthand for details on the new
shorthand mechanism (the new shorthand more closely resembles that
of csh).
clear
An alias for the \clear command, which causes the contents of the
current work buffer to be cleared and discarded. Also the screen
will be cleared if readline is compiled into sqsh.
reset
An alias for the \reset command, which causes the contents of the
current work buffer to be cleared and copied to history (if in
interactive mode).
exit [x]
quit [x]
An alias for the \exit [x] command, causes the current read-eval-
print loop to complete.
edit
vi
emacs
These are provided as aliases for the \buf-edit command. See
COMMANDS-Buffers for information on the interactions between
\buf-edit and aliases.
go Provided as an alias for the \go command (for obvious reasons).
help
An alias for the \help command.
In-Line \go
If the variable $semicolon_hack is set to 1 (on), then sqsh supports
what is called an in-line \go feature. This allows the current command
batch to be terminated and sent to the database in a single step by
appending a ';' onto the end of the current work buffer. This allows
1> sp_who;
To behave in the same manner as if you had typed:
1> sp_who
2> \go
Likewise, anything following the semicolon is passed to the \go command
just as if it was run as a normal command:
1> sp_who ; 2>/dev/null | more
Unlike most other isql replacements, sqsh attempts to be smart about
the semicolons. If a semicolon is contained within a set of single or
double quotes it will not be interpreted. This includes multiple
quotes. For example:
1> select "This is a multiple line
2> quote; it is smart!" ;
In the above example, only the second semicolon (the one at the end of
the line) will be interpreted.
SPECIAL VARIABLES
There are several options that are configurable via the command line
options to sqsh, however these are by no means complete. There are many
aspects of sqsh's behavior that may only be modified by setting special
variables. (In fact, the command line options really only set these
variables for you).
Variable Data types
Next to all of the variables that follow is the type of data with which
they may be set. Any attempts to set the variable with a type of data
that it does not accept will fail.
string
Any sequence characters.
boolean
A positive boolean value may be represented as either "True",
"Yes", "1", or "On" (case insensitive) and a negative boolean value
may be represented as "False", "No", "0", or "Off" (case
insensitive). However, internally the value of the variable will
always be represented as either a "1" or "0".
path
Must be the path name that is readable by the sqsh program.
int Must be one or more digits. Note that some variables also restrict
the range of the integer.
date-spec
This is a string of the format used to specify dates and times for
the date(1) command, or the strftime(3C) and cftime(3C) standard C
library functions. For example '%H:%M:%S' specifies a time of hours
in 24 hour format, followed by a colon, followed by minutes,
followed by a colon, followed by seconds.
float-format
A string of the format p.s, where p is the total precision of a
floating point value (the total number of digits to be displayed,
including those following the decimal) and s is the scale of the
value (the total number of digits following the decimal to be
displayed).
Variables
The following variables have special meanings within sqsh and the
setting of these variables alter the behavior of the shell.
$? (int)
This read-only variable may contain the following return value:
· The most recent error number returned from the SQL Server
(@@errno) of severity > 10 (above informational messages).
· The exit value of a previously executed pipe command.
· The return value of the most recently executed sqsh function.
$$? (int)
This variable may contain the result of the last executed \if
statement:
- 0 -
The test evaluated to False.
- 1 -
The test evaluated to True.
- 2 -
There was an error in the test specification.
$# (int)
Contains the number of arguments passed into the sqsh function or
script.
$* (string list)
Expands to the complete list of arguments supplied to the function
or script when invoked.
${0}...${N} (int)
Used to reference positional function arguments. Argument ${0} is
the name of the function being called, ${1} is the first argument,
etc.
$$ Expands to the process ID of the current running sqsh session.
DISPLAY
May contain the name of the DISPLAY the X-server uses to put the
XWindows result window when using \go -x. Defaults to the $DISPLAY
shell environment.
appname
Contains the name sqsh uses to identity itself to the server.
Defaults to sqsh-2.1.7. The application name can be retrieved from
the sysprocesses table like:
select program_name from master.dbo.sysprocesses where
spid=@@pid;
autouse (string)
Note: the meaning of this variable has been deprecated.
If $autouse is set, and the $database variable has not been set,
then this variable causes \connect to perform a "use $autouse" once
a connection has been established.
This variable may also be set using the -D command line option.
banner (boolean)
Turns off the banner message displayed on startup, this variable
defaults to 1 and may also be turned off using the -b command line
argument.
batch_failcount (int)
This internal variable is used to keep track of the number of
batches that have failed to execute (essentially, the number of
times that the error handler was called).
A batch is considered failed whenever an error of severity
$thresh_fail is encountered. When $batch_failcount reaches
$thresh_exit sqsh exits with an exit value of the total number of
batches that have failed. Setting $batch_failcount to the string ""
will cause it to reset to zero, any other value may have
unpredictable results.
See EXIT STATUS for details.
batch_pause (boolean)
Causes a "Paused. Hit enter to continue..." message to be displayed
after each batch is executed. This variable, in conjunction with
$echo is good for debugging SQL scripts specified with the -i
option.
bcp_colsep (string)
Used as a separator between columns during BCP style output (see
the $style configuration variable and the -m option to the \go
command). The default setting is "|".
bcp_rowsep (string)
Used as a separator between rows during BCP style output (see the
$style configuration variable and the -m option to the \go
command). Note that, a newline ("\n") is automatically appended
this value and should not be supplied. The default setting is "|".
bcp_trim (boolean)
Controls whether or not BCP style output trims trailing spaces from
fixed length columns. The default is "True".
chained (boolean)
If set then sqsh uses the "chained" transaction mode (aka
"AutoCommit off"). Setting this has NO effect on the current
connection. It can be set via the command line argument -n.
charset (string)
If this variable is set prior to establishing a connection with SQL
Server, then during the connection sqsh will request that the
server transform to and from the requested charset. After
establishing a connection, this variable is automatically set to
the current character set in use.
clear_on_fail (boolean)
Normally, whenever the \go command is run, sqsh clears the current
work buffer of its contents, moving them to history. Setting
$clear_on_fail to 0, leaves the current work buffer intact if a
failure is encountered while sending the contents to the database.
The default value is 1, or on.
colsep (string)
Causes the string colsep to be used to delimit SQL column output
columns, this defaults to " ", it may also be set via the command
line argument -s.
colwidth (int)
Used to control the maximum column width displayed by the pretty
display style (see $style below). If a row of a column exceeds this
width, it will be wrapped in a relatively visually appealing manner
at $colwidth characters. Note, however, that if there is enough
screen width to hold all columns $colwidth may be exceeded until
the width of the screen is reached.
database (string)
If this variable is set prior to establishing a connection to the
SQL Server, the a "use $database" is performed immediately after
the connection is established. Once a connection has been
established this variable will automatically be set to the current
database context.
date (date-spec)
This variable may be set with a date format (see the man page for
date(1)), and the variable expands to the current date in the
supplied format. The default format for this variable is %d-%b-%y
(e.g. 02-Feb-1996).
datetime (date-spec)
This variable may be set with a date format similar to $date and
$time and is used to control the display format of all SQL Server
DATETIME and SMALLDATETIME columns.
Note that this features relies upon the operating system specific
locale information for determining such things as the name of the
month and day, rather than going through the CT-Lib locale
information. This means that the date format could potentially
miss-match the locale as requested using the -z flag. For example,
if sqsh is run on an operating system configured for US English,
but requests French as the language of choice using -z, the use of
$datetime will cause all date information to be displayed in US
English rather than French.
Ordinary characters defined in the variable are left in place
without any conversion. Characters introduced by a '%' character
are replaced during display of a column value as follows:
[] Any contained between a pair of braces ('[' and ']') will be
removed when displaying SMALLDATETIME columns. This feature is
particularly useful for removing the seconds and milliseconds
values which are not applicable to SMALLDATETIME anyway. For
DATETIME columns, only the actual braces will be removed.
%a The abbreviated weekday name according to the current operating
system locale.
%A The full weekday name according to the current operating system
locale.
%b The abbreviated month name according to the current operating
system locale.
%B The full month name according to the current operating system
locale.
%c The preferred date and time representation for the current
operating system's locale.
%d The day of the month as a decimal number (range 0 to 31).
%D The date in US format (mm/dd/yy).
%H The hour as a decimal number using a 24-hour clock (range 00 to
23)
%I The hour as a decimal number using a 12-hour clock (range 01 to
12)
%j The day of the year as a decimal number (range 001 to 366).
%m The month as a decimal number (range 10 to 12).
%M The minute as a decimal number.
%p Either 'am' or 'pm' according to the given time value, or the
corresponding strings for the current operating system locale.
%r The time in 12-hour format (hh:mm:ss [AM|PM]).
%s Seconds since the epoc (1970-01-01 00:00:00 UTC) (this is not
supported on all systems).
%S The second as a decimal number.
%T The current time in 24-hour format (hh:mm:ss).
%u The millisecond as a decimal number.
%U The week number of the current year as a decimal number,
starting with the first Sunday as the first day of the first
week.
%W The week number of the current year as a decimal number,
starting with the first Monday as the first day of the first
week.
%w The day of the week as a decimal, Sunday being 0.
%x The preferred date representation for the current locale
without the time.
%X The preferred time representation for the current locale
without the date.
%y The year as a decimal number without a century (range 00 to
99).
%Y The year as a decimal number including the century.
%Z The time zone (e.g., EDT), or nothing if not time zone is
determinable.
%% A literal '%' character.
debug (string)
If sqsh has been compiled with debugging enabled (-DDEBUG), this
variable may be used to control the amount of debugging output
displayed. $debug may be set to a pipe (|) delimited (logical OR)
set of the following words to turn on various pieces of debugging:
ALIAS, AVL, BCP, DISPLAY, ENV, ERROR, EXPAND, FD, JOB, READLINE
(abbr. RL), RPC, SCREEN, SIG, SIGCHLD (or SIGCLD) or ALL.
defer_bg (boolean)
Normally, when a job is run in the background (via a '&' on the
command line), the output of the job is deferred to a temporary
file (located in $tmp_dir) until the user requests the output to be
displayed using \show jobid. This way the results of the job will
not interfere with what the user is doing. Setting this variable to
false will result in no deferred output files being created and
output sent to the screen immediately
echo (boolean)
Setting $echo to on (1) causes each command submitted to the
database via the \go command to be displayed prior to the output.
This variable defaults to 0 (or off), and may also be set using the
-e command line option.
encryption (boolean)
Setting the $encryption variable prior to establishing a connection
to the server will cause the login connection to be initiated using
client-side password encryption. This variable may also be set
using the -X command line option.
exit_failcount (boolean)
Settings this value to 1 causes sqsh to return an exit status of
$batch_failcount rather than 0, upon a non-error termination. See
EXIT STATUS for details. The default value is 0.
exit_value (int)
When you exit sqsh by specifying an exit code, like \exit 3 or
using one of the aliases exit or quit commands, then this value is
assigned to the $exit_value variable. You can also assign a value
using the \set command. When sqsh determines this variable has a
non-zero value during termination, this value will be used as exit
code. See EXIT STATUS for details.
expand (boolean)
By default when the \go command is executed, the contents of the
current work buffer is expanded of all environment variables prior
to being sent to the database for execution. By setting this
variable to "0", the buffer will no longer be expanded before being
sent to the database. This is useful when you either (1) have
strings in the buffer that contain a '$' and you don't want them to
be expanded, or (2) for performance reasons; it takes time (and an
extra copy of the buffer) to perform the variable expansion.
filter (boolean)
Toggles filtering of the SQL batch through an external program
(defined by the $filter_prog variable, below) prior to being sent
to the SQL Server. Default is '0', or 'off'.
filter_prog (string)
Defines the external program through which the SQL batch will be
filtered prior to being sent to the SQL Server. This variable is
ignored if $filter is set to '0' or 'off'. The default is 'm4 -'.
float (float-format)
Defines the display format (the precision and scale) for all
floating point values displayed by sqsh. The default is '18.6'.
Note that values exceeding the defined precision are not truncated,
so setting this value too low may cause columns in a result set to
be miss-aligned.
footers (boolean)
Toggles the "(%d rows affected)" following a result set. The
default for this variable is '1'.
headers (boolean)
Toggles the column headers preceding a result set. The default for
this variable is '1'.
help_dir (path)
This is the location of the help files used by the \help command,
typically it defaults to something like /usr/local/lib/sqsh/help.
hist_auto_save (int)
When variable $histsave is on and the $hist_auto_save variable has
a value greater than 0, then the history will be automatically
saved to $history after $hist_auto_save modifications of the
history buffers. When the value is 0 (default), then no automatic
history save will be performed.
histnum (int)
Contains the history number that will be assigned to the current
command batch as soon as the \go command is executed. This variable
should be considered read-only. See also the discussion on the
$histunique variable.
history (path)
This is the location of the history file used to store and retrieve
a user's history during start-up and shutdown. This defaults to
$HOME/.sqsh_history. This variable is expanded each time it is
referenced by sqsh, much in the same way that $prompt is referenced
each time the prompt is displayed.
history_shorthand (boolean)
This variable is only meaningful within an interactive session. If
set, it turns on the ability to append any named buffer or history
buffer onto the current work buffer in a 'sh' history style, such
as '!40'. Be careful with this feature, sqsh is not terribly
intelligent with looking for history shorthand, so it is possible
that it may get confused (although, it is smart enough to ignore
!'s in quoted strings).
histsave (boolean)
The value of this variable is used by sqsh to indicate whether the
history should be saved to $history prior to termination of sqsh.
histsize (int)
The value of this variable is used to alter the maximum number of
history entries are maintained by sqsh (the default is 10). Note
that decreasing the value of this variable causes some history
entries to be lost.
histunique (boolean)
If set, sqsh maintains a MRU-LRU order of executed buffers and does
not store duplicate command buffers. For example, observe the
following situation:
LINUX1502.user1.master.1> \history
(1) sp_who
(2) grant role mon_role to sa_role
(3) select * from monProcessActivity
(4) select @@authmech,show_sec_services()
(5) select @@servername,@@authmech,show_sec_services()
LINUX1502.user1.master.1> sp_who
LINUX1502.user1.master.2> go
... output omitted
LINUX1502.user1.master.1> \history
(1) grant role mon_role to sa_role
(2) select * from monProcessActivity
(3) select @@authmech,show_sec_services()
(4) select @@servername,@@authmech,show_sec_services()
(5) sp_who
sp_who is the last executed command and the buffer - originally the
last in the list - is now on top of the list. When an already
existing buffer is reused, the value of the $histnum variable is
not changed.
hostname (string)
Used during the connection process to indicate to SQL Server the
name of the host from which sqsh is connecting. This variable may
also be set using the -H flag.
ifs (string)
The list of Internal Field Separators.
ignoreeof (boolean)
By default, sqsh terminates if the user presses ^d (control-D) on
an empty line and readline support is compiled in. If $ignoreeof is
set in the sqshrc file you get a warning message instead:
CTRL-D: Use "exit" or "quit" to leave the sqsh shell.
This is equivalent to using "set -o ignoreeof" in the bash shell.
interactive (boolean)
This is a variable used internally and should probably not be
altered by the user. If $interactive is '0', then the prompt is not
displayed, the history is neither read nor written and some user
messages are suppressed.
interfaces (path)
This is the full path name of the interfaces file, it defaults to
$SYBASE/interfaces.
keytab_file (string)
Used in Kerberos and DCE user authentication security mechanisms.
Corresponds with the -K startup option.
See also the discussion on Kerberos Support.
keyword_completion (int/string)
This variable only applies if GNU Readline support has been
compiled into sqsh. $keyword_completion is used to control the TSQL
keyword completion feature in readline, and may be set using either
an integer between 0 and 4, or one of the strings none, lower,
upper, smart, or exact. If it is set to either 0 or none, then no
keyword completion is performed (this is the default). lower or 1,
causes sqsh to complete the keyword in lowercase, regardless of the
case that the partially completed keyword was typed. upper or 2
forces completion to be performed in upper case, smart, or 3, bases
the decision on case upon the first character of the partial
keyword, and exact completes the keyword in exactly the same case
as defined in the .sqsh_words (for the built-in TSQL keywords, this
will be lower case).
keyword_file (string)
If readline support has been compiled into sqsh, and sqsh is being
run in interactive mode, the contents of this file are used for
keyword tab completion by readline rather than the default set of
TSQL syntactical keywords. The default is $HOME/.sqsh_words.
language (string)
The $language variable is used while establishing a connection to
the server to specify the national language used to display system
prompts and messages. The variable will automatically track the
current language setting of the server. This may also be set via
the -z flag.
lineno (int)
This is an internal variable and should not be altered by the user.
It is used to maintain the line number that is being typed into
within the current work buffer.
linesep (string)
Used to configure the line separator for the horizontal display
style, this defaults to "\n\t".
lock (string/write-only)
Defines the password to be used by the \lock command. If unset or
set to the string "NULL", then the UNIX password of the user
running sqsh is used instead (if possible). Note that $lock will
always expand to the string "*lock*" if referenced.
login_timeout (int)
The number of seconds to wait when attempting to create a new
connection to a data server. Default is 0 (infinite wait). See also
the -T command line option.
max_timeout (int)
Controls the number of times a query needs to reach its time-out
value before the session is aborted. See $query_timeout and the -Q
command line flag. The following messages will be displayed and
sqsh exits with value 255 when the $max_timeout limit is reached.
Query or command timeout detected, session aborted
The client connection has detected this x time(s)
Aborting on max_timeout limit
maxlen (int)
Controls the maximum amount of data that will be displayed (in any
display mode) in a single column. This setting will automatically
truncate the output of particularly large data types (such as TEXT)
to the value supplied. The default setting is 8192 bytes (8KB).
newline_go (boolean)
This flag is used as a horrible kludge to support an "empty" alias
for the \go command, that is, the equivalent of supplying "-c ''"
or just "-c" on the command line. When on, an empty line is
interpreted as a call to the \go command. This feature is not
recommended but is supplied for completeness.
output_parms (boolean)
Flag used to enable or disable the display of output parameter
result sets from stored procedures. The default is to enable the
display.
packet_size (int)
Defines the size of the TDS packets used to communicate with SQL.
Changing the value of the variable will not affect the current
connection but will take effect upon the next \reconnect command.
Specifying a value of NULL indicates that the default packet size
is desired.
password (string/write-only)
This is the user's current password. A NULL password may be
assigned using an explicit "NULL" string. For security reasons,
when referenced the $password variable will always expand to the
string "*password*".
password_retry (boolean)
When the variable is on and sqsh started in interactive mode, sqsh
will ask for the password again if login failed. When set to 'off',
sqsh will terminate immediately. Default is on.
principal (string)
Used in Kerberos user authentication as the Server principal name
when it differs from the $DSQUERY name. Corresponds with the -R
startup option.
See also the discussion on Kerberos Support.
prompt (string)
This variable is used by sqsh to build your current prompt. Any
variables contained within $prompt are expanded each time the
prompt is displayed. The default value for this is '${lineno}> '.
See also the discussion on color support below.
prompt2 (string)
This contents of this prompt are expanded and displayed during
interactive use when sqsh requires additional input, such as during
a line continuation. The default value is '--> '.
query_timeout (int)
Number of seconds to wait for a query to return data. If the
timeout is reached the query is aborted (canceled). See also
$max_timeout and the -Q command line option.
rcfile (path)
Contains a colon (:) delimited list of sqsh resource (sqshrc)
files. The default setting is /etc/sqshrc followed by
$HOME/.sqshrc).
readline_history (string)
If readline support has been compiled into sqsh, the contents of
the readline line-by-line history will be written to the file
specified by the $readline_history variable. The default is
$HOME/.sqsh_readline.
readline_histsize (int)
If readline support has been compiled into sqsh, the value of
$readline_histsize specifies the number of lines that are saved in
the readline line-by-line history. Setting this to a value of 0
causes every line to be saved. The default value is 100.
real (float-format)
Defines the display format (the precision and scale) for all real
values displayed by sqsh. The default is '18.6'. Note that values
exceeding the defined precision are not truncated, so setting this
value too low may cause columns in a result set to be miss-aligned.
repeat_batch (boolean)
When set to On or True, a \go executed with an empty SQL Buffer
will cause the previous batch to be re-executed.
secmech (string)
The name of the security mechanism used for user authentication.
For instance csfkrb5. When using the -Z option, the name of the
security mechanism can be specified, or when no secmech is
supplied, the OpenClient will use the default, i.e. the first
security entry from the $SYBASE/$SYBASE_OCS/config/libtcl.cfg file.
Note that the name used must match the name of the corresponding
secmech entry in the objectid.dat file. When the connection to the
server is setup, the actual secmech name will be stored in the
$secmech variable.
secure_options (string)
Describe the security options used for user authentication security
mechanisms. Corresponds to the -V startup option.
See also the paragraph on Kerberos Support.
script (string)
If sqsh is run using the -i flag, then this variable contains the
name of the script being executed.
semicolon_cmd (string)
When $semicolon_hack (see below) is enabled, the contents of this
variable is executed when a semicolon is encountered in the SQL
Buffer. This variable defaults to the string '\go'.
semicolon_hack (boolean)
Toggles on the ability to use a ';' as an in-line command
terminator. This feature is not recommended and is only in here
because enough users complained. See section COMMANDS, In-Line Go.
session (string)
The location of the session file that will be processed just before
connecting to a server. The variable will be expanded so it may
contain environment variables.
SHELL (string)
The name of the shell to be used to execute pipes and to be used by
the \shell command (default '/bin/sh').
statistics (boolean)
Setting $statistics to 1 causes timing statistics to be displayed
upon the successful execution of every batch of SQL. This variable
may also be set via the -t command line flag, or by supplying -t to
the \go command. $statistics defaults to 0.
style (string)
Selects result set display style. Currently eight styles are
supported. The horiz (which may also be defined as hor or
horizontal), closely resembles the output of isql, with the
traditional columnar output.
The vert (or vertical) style rotates the output, so that every line
is represented by a column name followed by a column value. This is
nice for looking at particularly wide output.
The bcp style displays results in a format amenable to bcp'ing the
result set back into another table. That is, every column value is
separated by $bcp_colsep with the final column separated by
$bcp_rowsep followed by a newline (\n). If $bcp_colsep or
$bcp_rowsep are not defined then '|' is used as the default
separator. Note that this output does not work well with COMPUTE
columns, and uses the default conversion methods for all data types
(that is, datetime columns may truncate the millisecond).
The csv display style outputs all result sets in the form of a
comma separated construct. This mode is ideal to import result sets
into spreadsheet programs, for instance.
The html display style outputs all result sets in the form of an
HTML <TABLE> construct. This mode is ideal for the use of sqsh as a
CGI application.
The meta display style outputs only the meta-data information
associated with the result and discards the actual row results.
This mode is useful for debugging the result sets generated from a
full passthru Open Server gateway, or for those interested in what
is really coming back from the server.
The pretty display style generates a fluffy table-like output using
regular ASCII characters for borders. This mode does not perform
any explicit column wrapping, like the horiz display mode. However,
the $colwidth variable can be used to control the maximum width of
a given column on the screen. If the column exceeds $colwidth
characters wide, it is wrapped in a relatively visually appealing
manner. Note that $colwidth may be exceeded if there is enough
screen width to hold the columns without wrapping.
The none display style suppresses all results from being displayed
(however it does actually retrieve result information from the SQL
Server). This is particularly useful when used with the -p flag (or
the $statistics variable) for gathering accurate performance
statistics.
term_title (string)
When this variable is set, sqsh will reset the name of the current
terminal (xterm) window it is running in. Works for xterm, rxvt,
putty and MS-Windows CMD windows. The name consists of the sqsh
startup name appended with the expanded value of the $term_title
variable.
thresh_display (int)
Sets the minimum SQL Server error severity that will display a
message to the user, the default is 0 and valid ranges are between
0 and 22, inclusive.
thresh_exit (int)
Defines the maximum number of errors of severity level $thresh_fail
that may be encountered before sqsh aborts. This is useful
primarily for non-interactive scripts, but is allowed on an
interactive session. Setting $thresh_exit to a value of 0 disables
this feature. See section EXIT STATUS for details.
thresh_fail (int)
Sets the minimum SQL Server severity level that is to be considered
a failed batch. The minimum for this value is 0 (meaning any error
that is not an information message), and the maximum is 22.
Whenever $thresh_fail is crossed, the variable $batch_failcount is
incremented by 1. See section EXIT STATUS for details.
time (date-spec)
This variable may be set with a time format (see the man page for
date(1)), and the variable expands to the current time in the
supplied format. The default format for this variable is %H:%M:%S
(e.g. 14:32:58).
tmp_dir (path)
This contains the directory to which temporary files used
internally by sqsh are to be written. These files are generated
either during buffer editing (the \buf-edit command), or to
maintain output defer files for background jobs. The default value
for this variable is /tmp.
username (string)
The name of the user currently connected to the database.
version (none)
This read-only variable contains the current version number.
(sqsh-2.1.7)
width (int)
The current width of the SQL output.
xgeom (string/int)
If X11 support is compiled into sqsh, this value is used to
configure the default window size (in characters) of the X display.
This variable must be of the format WxH or just W, where W is the
width of the window and H is the height of the window. If the
height of the window is not supplied, then 25 lines is assumed. If
$xgeom is not set, then $width is used as the default width and the
height is assumed to be 25. If neither is set, then 80x25 is
assumed.
xwin_title (string)
If X11 support is compiled into sqsh and an X11 result windows is
requested by using the -x parameter of the \go or \rpc commands,
then this variable will be used to set the title name of the
window. Can be temporarily overridden with the -T option of the \go
and \rpc commands.
Script Execution
As with most shells, sqsh allows a file containing SQL and script
commands to be executed directly via the magical UNIX #! convention. On
most UNIX platforms, when the operating system encounters the bytes #!
as the first two bytes of an executable file it will automatically pipe
the file through the interpreter specified immediately after the #!.
For example, to create an executable sqsh script to run sp_who, you
simply need to create a file like so:
#!/usr/bin/sqsh -i
sp_who
go
Thus, if your sp_who script is executed directly, it will automatically
launch "/usr/bin/sqsh -i sp_who" for you.
And, to make things even more flexible, sqsh supports positional
parameters, similar to most shells, of the form ${n} which will expand
to the nth argument to your sqsh script. For example:
#!/usr/bin/sqsh -i
sp_who ${1}
go
will cause the sp_who stored procedure to be executed with an argument
of the first command line parameter supplied to the sp_who shell
script.
Note that positional parameters must be contained between braces to
avoid conflicts with the TSQL money data type (without the braces, the
variable will not be expanded).
EXIT STATUS
One of the major complaints of isql is that it provides no facility to
detect when an error condition occurred while it is performing
processing. sqsh provides a rather complex, but flexible mechanism for
returning meaningful information concerning its reason for exit in the
form of an exit status (see exit(3)).
When sqsh begins execution two handlers are associated with the current
connection to the database, one is a message handler which is
responsible for displaying the text of any SQL Server messages or
errors, and the other is an error handler, which is responsible for
determining what to do with an error condition (bear with me, these are
only loose descriptions). And, associated with each message and error
condition is a severity level, between 0 and 22 (informational message
to fatal condition).
Associated with these two message handlers are several variables that
are used to either control their behavior, or are used as indicators by
the message handler:
$thresh_display
This variable is used by the message handler to determine the
minimum error severity which will cause a message to be displayed.
By default this is 0, which will display all messages (with a
couple of exceptions). Setting this to 1, for example, would
suppress informational messages such as the output of set showplan
on.
$thresh_fail
This variable is used by the error handler to determine which error
severity is considered by sqsh to be a failure. Normally, this
defaults to 11 which indicates that any error, other than
informational messages, is a failure. The next variable will
explain the importance of this value.
$batch_failcount
This variable should be considered read-only, and contains the
total number of times that batches have caused an error of severity
$thresh_fail or more. The only value that is valid to explicitly
set this value to, is "" (the empty string), which will reset this
value to 0, any other value may have unpredictable results.
$thresh_exit
This variable is used to determine the limit at which
$batch_failcount will cause sqsh to exit. If $thresh_exit is 0,
then this feature is disabled. In other words, if $batch_failcount
= $thresh_exit and $thresh_exit is greater than 0, then sqsh will
exit, returning $batch_failcount as an exit status.
Note that, unless $exit_failcount is set to 1, sqsh will exit with
0 if the total number of failures does not reach $thresh_exit.
$exit_failcount
This variable is used only when sqsh would normally exit with a
success status (0), this causes it to instead exit with a value of
$batch_failcount (which may, itself, be 0).
$exit_value
When this variable is non-zero, it will override the
$exit_failcount and $batch_failcount values and just exit the value
of $exit_value. This variable may be explicitly set using the \set
command, or implicitly using \exit x and its aliased counterparts.
To recap, here is a list of error codes that may be returned by sqsh
upon exit, and the reason that they could be returned:
- 0 -
No error has been encountered.
- 1...253 -
Between 1 and 253 batches have failed (if you run more than 253
batches, the exit status of sqsh is undetermined...I may fix this
in the future).
- 254 -
An explicit \abort was called, or a SIGINT (^C) was issued during a
non-interactive session.
- 255 -
A general error condition has occurred, such as a bad command line
argument to sqsh, memory allocation failure, file access error,
etc.
The following sections provide detailed examples of combinations of
variable settings and the results produced upon exit with certain
failure conditions. It is assumed the $exit_value variable contains 0
in the next examples.
thresh_display=0, thresh_fail=0, thresh_exit=1
With this combination, all error messages will be displayed as they
happen, and every error will be considered an failure condition.
Upon reaching the first error, sqsh will abort with an exit status
of 1, or the total number of failures (the $batch_failcount
variable). However, if nothing goes wrong during the whole process,
a zero is returned.
thresh_display=0, thresh_fail=0, thresh_exit=3
This combination will cause all error conditions to be displayed
and all of them to be considered a failure condition. Upon reaching
three total failed batches, sqsh will exit with a status of 3.
However if 0, 1, or 2 batches fail, then 0 is returned.
thresh_display=22, thresh_fail=0, thresh_exit=3
This behaves the same as the previous example, with the exception
that all error messages will be suppressed from being displayed.
This is particularly useful if you just care about the exit value
more than the actual error.
thresh_display=0, thresh_fail=2, thresh_exit=1
This will cause the first error of severity 2 or higher to be
displayed and cause sqsh to exit with a failure condition of 1.
thresh_display=0, thresh_fail=0, thresh_exit=3, exit_failcount=1
This is identical to the second example, above, however sqsh will
return the total number of batches that failed even if
$batch_failcount does not reach 3.
exit_value=nonzero
This will override all conditions explained above and just exit the
specific value.
Miscellaneous
Colorizing sqsh prompts, etc.
Color codes are presented as a string like {1;2;3}. If sqsh encounters
a { (curly brace) in the prompt string it will assume a color-code is
supplied and will act as such. No checks will be performed on the
validity of the color-code definition itself. The color definition
consists of three values separated by a semicolon.
The first code defines the Color Attribute Code with possible values:
0=none 1=bold
The second value defines the Text Color Code: 30=black 31=red 32=green
33=yellow 34=blue 35=magenta 36=cyan 37=white
The third value defines the Background Color Code: 40=black 41=red
42=green 43=yellow 44=blue 45=magenta 46=cyan 47=white The last color-
code for the background may be omitted.
Not all color and attribute combinations will present good results,
depending on your terminal type and color scheme. But the following
values work OK on a xterm with a creamy white background color in Linux
as well as rxvt in Cygwin with a black background window:
Prompt: Blue text in white background "{0;34;47}"
Command text: Yellow text "{0;33}"
sqsh will translate the color-codes to an actual color-code string that
is presented to readline: for example "\001\033[0;36;47m\002". Note
that if you want to use curly brackets in your prompt, you have to
escape colorization by specifying a double brace, like {{...}}. For
example:
\set prompt_color='{0;34;47}'
\set text_color='{0;33}'
\set prompt='$prompt_color{{$DSQUERY.$username.$database.$lineno}}>$text_color '
Color support is automatically available if sqsh is compiled and linked
with readline support enabled.
FILES
Defaults: $HOME/.sqshrc, $HOME/.sqsh_session, $HOME/.sqsh_history,
$HOME/.sqsh_readline, $HOME/.sqsh_words, $tmp_dir/sqsh-dfr.*,
$tmp_dir/sqsh-edit.* These can all be modified using the internal sqsh
variables described above.
BUGS
The addition of flow-of-control expressions has extended sqsh way
beyond the scope of its original design, and it is quite obvious from
using the features they are hacked in and are rather clunky (although
still quite usable). As a result, the processing of these expressions
is rather slow (when compared to bourne shell), and the error reporting
doesn't lend itself to debugging large scripts. The development of
1000+ line scripts is discouraged.
The combination of backgrounding and pipes does not work properly right
now. I know why this is happening, but haven't determined an elegant
solution to it just yet. What happens is, when a background job is run
that incorporates a pipe-line, sqsh will suspend until the job is
complete, which is obviously not what you desire. To test this, try the
following:
1> select * from syscolumns
2> go | grep id &
You will find that you do not get your prompt back until the job
completes. If you want a technical explanation of why this is
happening, send me e-mail at the address at the end.
I would like to support all of the flags available in isql right now.
This shouldn't be very hard.
No complaints about spelling or grammar. I hate documentation, so count
yourself lucky that you have a manual page at all.
2.1.7 2010-02-17 sqsh(1)
